The advent of integrated circuitry has given rise to the need for integrated circuit (IC) packages that will both house and protect the integrated circuit die. These integrated circuit packages provide a mechanism for making electrical interconnection between the circuits on the integrated circuit die and the leads that are utilized to make electrical interconnections to circuits, power, and ground external to the integrated circuit die. For early types of integrated circuits, the packaging of the integrated circuits was relatively straightforward and generally involved an array of leads arranged around a die cavity to be electrically connected to associated die pads. There were also relatively few circuits on each integrated circuit die, and the circuit operational rates were by modern day standards relatively slow. Accordingly, size and power was relatively less important than the consideration of economical assembly.
Across virtually all applications, there continues to be growing demand for reducing size and increasing performance of integrated circuits. The seemingly endless restrictions and requirements are no more visible than with products in our daily lives. Smaller and denser integrated circuits are required in many portable electronic products, such as cell phones, portable computers, voice recorders, etc. as well as in many larger electronic systems, such as cars, planes, industrial control systems, etc. As the demand grows for smaller electronic products with more features, manufacturers are seeking ways to include more features as well as reduce the size of the integrated circuit packages. To meet these needs, packaging technologies are increasingly using smaller form factors with more circuits.
As the integrated circuit technology advances, more circuit cells can be fabricated in a similar die area so that substantially increased functionality can be accomplished on a given integrated circuit die. The added functionality and increase in the number of circuits generally involves a larger amount of power. As physical sizes decrease and the numbers of circuits increase, it has become necessary to develop integrated circuit packages that would accommodate the increased power. Both integrated circuit users and integrated package manufacturers worked to develop integrated circuit package systems that would accommodate the higher power requirements.
Most of the thermally enhanced molded ball grid array (BGA) packages (bump or non-bump die) focus on attaching a heatspreader to the top of an integrated circuit die and/or a substrate. One such attempt to attach the heatspreader includes the heatspreader touching the integrated circuit die surface but no protection for the die from crashing in the top mold cavity during molding. An integrated circuit package generally includes a protective housing, which surrounds the integrated circuit die. The protective housing is usually filled with a liquid potting material, or other encapsulant, which then hardens in situ. During the introduction of the liquid, however, the mold, molding material or other elements are susceptible to crashing, such as collapsing, deforming, or protruding to the integrated circuit die.
With a heatspreader attached to the top of the integrated circuit die, there will be a greater risk of crashing the die in the top mold cavity during the molding process. This is mainly because of height variations or warping during processing and fabrication that affect the design tolerances. Dimensional variation comes in several different ways and processes affecting the total height. A sample of some sources affecting the total height include the following: bondline thickness (BLT) variation during die attach, die tilt, die thickness variation during backgrind, heatspreader dimensional tolerance, warping and dimensional changes due to shrinkage and expansion in part due to thermal cycles such as in assembly processes.
Thus, a need still remains for an integrated circuit package system to provide improved reliability and manufacturing yield with heatspreaders. In view of the increasing demand for improved density of integrated circuits and particularly portable electronic products, it is increasingly critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.